AnswersLAUSD-Chemistry in the Earth System BCumulative Exam

Cumulative Exam — Cumulative exam Answers

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According to the collision theory, which is required for a high number of effective collisions?

A
a very low amount of force from colliding molecules
B
a very low amount of kinetic energy from colliding molecules
C
molecular collisions that have very specific orientations
D
molecular collisions with energy to overcome activation energy
22
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The following reaction occurs in a car’s catalytic converter.2NO(g) + 2CO(g) N2(g) + 2CO2(g) Which answer best describes the reducing and oxidizing processes in this reaction?

Question illustration
A
NO and CO are both reducing agents.
B
NO and CO are both oxidizing agents.
C
The oxidation state of nitrogen in NO changes from +2 to 0, and the oxidation state of carbon in CO changes from +2 to +4 as the reaction proceeds.
D
The oxidation state of nitrogen in NO changes from 0 to +2, and the oxidation state of carbon in CO changes from +4 to +2 as the reaction proceeds.
23

Aristo was riding in a car and noticed a pond that was covered in algal blooms due to excess phosphorus in the water. Which of these other features in the landscape could be the reason for the high levels of phosphorus?

A
many cars
B
cow pasture
C
solar panels
D
forest
24

Which best describes the function of a centrifuge?

A
to separate the solute from the solvent
B
to separate the dissolved part of a solution into layers
C
to separate a mixture by heating it for a long period of time
D
to separate the undissolved particles of a mixture into layers
25

Which statement provides the complete explanation of how renewable and nonrenewable resources differ?

A
They differ in the amount they are found in nature.
B
They differ in the rate they are replaced.
C
They differ in the available amount and rate they are used and replaced.
D
They differ in the rate they are used.
26

How do changes in wind currents affect the short-term climate in a region?

A
Prevailing winds can cause a milder climate with heavy rain.
B
Global winds can cause a longer summer.
C
Prevailing winds can cause heavy rains or a dry climate.
D
Global winds can cause a longer winter.
27

A student requires 2.00 L of 0.100 M NH4NO3 from a 1.75 M NH4NO3 stock solution. What is the correct way to get the solution?Use .

Question illustration
A
Measure 114 mL of the 1.75 M solution, and dilute it to 1.00 L.
B
Measure 114 mL of the 1.75 M solution, and dilute it to 2.00 L.
C
Measure 8.75 mL of the 1.75 M solution, and dilute it to 2.00 L.
D
Measure 8.75 mL of the 0.100 M solution, and dilute it to 2.00 L.
28

The following half-reaction method is used to balance oxidation-reduction equations.(1) Determine which atoms change oxidation state from reactant to product in the reaction.(2) Identify and write half reactions (oxidation and reduction).(3) Return to the original chemical equation to balance it.(a) Insert the coefficients from the half reactions first.(b) Inspect the number of each atom on each side for all elements.Which important step is missing from this procedure?

A
Check other reactions similar to this one.
B
Name the elements that are involved in the reaction.
C
Make sure the reduction half reaction is identified first.
D
Balance the half reactions based on the number of electrons.
29

Water is dissolved into n-butanol (a polar liquid). Which is the second step at the molecular level as water dissolves into n-butanol?

A
n-Butanol mixes with water.
B
Water molecules are carried into n-butanol.
C
n-Butanol molecules surround water molecules.
D
n-Butanol molecules are attracted to the surface of the water molecules.
30

A beam of light passes though a liquid in a test tube without scattering. Which type of mixture is most likely in the test tube?

A
colloid
B
emulsion
C
solution
D
suspension
31

Which effect of long-term environmental change is the driving force behind evolution?

A
adaptation
B
extinction
C
migration
D
speciation
32

What happens when the Sun emits more energy than normal?

A
Solar flares and sunspots occur, increasing Earth’s temperature.
B
Sunspots and volcanic eruptions occur, increasing Earth’s temperature.
C
Volcanic eruptions and movement of continents occur, decreasing Earth’s temperature.
D
Movement of continents and solar flares occurs, decreasing Earth’s temperature.
33

Which is a difference between the Paleozoic and Mesozoic era?

A
Animals lived in the water during the Mesozoic and on land in the Paleozoic.
B
The first birds emerged in the Paleozoic era while mammals first emerged in the Mesozoic.
C
Many different species of dinosaurs lived in the Mesozoic, but they all died off in the Paleozoic.
D
Animal complexity increased during the Paleozoic while the first flowering plants appeared in the Mesozoic era.
34

Consider the balanced equation below.N2H4 + 2H2O2 N2 + 4H2OWhat are the mole ratios of hydrazine (N2H4) to hydrogen peroxide (H2O2) and hydrazine to water?

Question illustration
A
1:2 and 1:4
B
1:3 and 1:4
C
1:2 and 3:5
D
1:3 and 3:5
35

Which statement accurately describes short-term environmental changes?

A
Short-term environmental changes cause changes in genetic makeup.
B
Short-term environmental changes do not happen suddenly with little warning.
C
Short-term environmental changes do not affect organisms within an ecosystem.
D
Short-term environmental changes immediately affect organisms in the environment.
36

Based on the activity series provided, which reactants will form products?F > Cl > Br > I

A
CuI2 + Br2
Option A
B
Cl2 + AlF3
Option B
C
Br2 + NaCl
Option C
D
CuF2 + I2
Option D
37

What is a common use of bases?

A
as a component of vinegar
B
as a component of car batteries
C
to make foods tart
D
to reduce indigestion
38

Which causes an increase in greenhouse gases?

A
change in wind patterns
B
strengthening of hurricanes
C
burning of wood and coal
D
movement of warm ocean waters
39

Which is a feature of a single replacement reaction?

A
Substance XYZ breaks down into X and YZ.
B
Substance G reacts with compound XY to form GY and X.
C
Substance X burns rapidly in the presence of oxygen.
D
Substance QR and GT exchange ions with each other.
40

Pure water at 25°C

A
ionizes in the presence of acid to form an equilibrium in which
Option A
B
ionizes in the presence of acid to form an equilibrium in which
Option B
C
self-ionizes to form an equilibrium in which
Option C
D
self-ionizes to form an equilibrium in which
Option D

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